A variety of solar devices have been proposed, many of which have flat plate collectors that require pumps, electronic controls, and additional water storage which may include increasing the capacity of conventional electrical heaters used as part of a hot water system. The efficiency of such flat plate systems may also be affected by the angle at which the sun hits the plate. Thus, the plate may have to be mechanically or manually turned to obtain full exposure to the sun's rays. Attempts have been made to overcome this angle orientation problem.
U.S. Pat. No. 4,256,092 to Gutermuth et al. shows a solar radiation converter which includes a black insulated housing with a front glass wall and a plurality of blackened rotationally symmetrical balls or cylinders pivotally disposed within the housing as absorber elements and turned by a flowing heat transfer medium such as water.
U.S. Pat. No. 3,587,559 to Nonaka teaches an apparatus for heating water by solar rays comprising a plurality of spherical lenses positioned in a box covered by glass at the side facing the sun, a plurality of heat collecting members each positioned below each of the spherical lenses, each of the heat collecting members being lined with a superheat resisting carbon impregnated cloth at the area subjected to focused rays, and a continuous water pipe extending in a number of convolutions within the box.
U.S. Pat. No. 4,056,093 to Barger discloses a solar heating unit including an upwardly opening generally hemispherical double wall boiler including spaced inner and outer hemispherical walls defining a closed chamber therebetween in which to receive a liquid to be heated. An upwardly convex spherical lens structure is supported over the boiler and comprises a closure for the area enclosed within the boundaries of the inner hemispherical wall of the boiler and the lens assembly or structure functions to direct light rays incident thereon onto the inner wall of the boiler. The solar heater additionally includes a hollow downwardly opening transparent hemispherical cover of generally the same radius of curvature as the boiler and which is secured over the lens assembly in outwardly spaced position relative thereto with the center of curvature of the cover substantially coinciding with the center of curvature of the lens assembly. Water or other liquid inlet and outlet structure is provided on a second form of the invention for admitting liquid to be heated into the interior of the boiler between the inner and outer plates thereof and for withdrawing heated liquid from within the boiler.
U.S. Pat. No. 4,057,048 to Maine discloses a solar heat-collecting structure comprising a series of interconnected transparent lenses forming a dome-shaped roof for receiving direct solar radiation and for transmitting such radiation through the lenses into the enclosure formed thereby and focusing it onto a shallow tray of water forming a floor of the enclosure.
U.S. Pat. No. 4,116,223 to Vasilantone teaches a solar energy unit comprising a housing adapted to be mounted on the roof of a building or otherwise suitably supported. The housing has a central cavity which contains a reservoir for a heat absorbing liquid. A heat exchanger containing a circulating heat exchange fluid is immersed in the heat-absorbing liquid. The heat exchange fluid circulates to areas to be heated. A substantially hemispherical and transparent dome covers the upper end of the housing and the cavity and is provided with prismatic facets on its inner surface to magnify the sun's rays and to focus or concentrate the rays on the heat-absorbing liquid.
U.S. Pat. No. 4,236,507 to Vincent teaches a solar heater for air. The solar heater has a shape like a dome with a transparent outer cover and transparent inner cover. A dead air layer is inbetween covers. Inside the dome is a collector that holds up the covers and converts the solar rays to heat. Air or gas is circulated through the solar heater from an input pipe on one side to an output pipe on the other side, obtaining heat from the collector and base by conduction and radiation.
There is thus a need for a unified solar heater and storage system which can function as a passive system without the requirements of pumps and/or expensive electronics, and which is adaptable for use with a domestic hot water system.
It is, therefore, an object of the present invention to provide a unitary solar heating and storage unit capable of providing hot water for home and/or industrial use.
It is a further object of this invention to provide a solar heating and storage unit which does not have to be adjusted to any change in the angle of exposure to the sun.
It is yet another object of this invention to provide a solar heater and storage unit which minimizes heat loss to the atmosphere.
It is a further object of this invention to provide a solar unit which will reduce the cost of using solar energy.